Dental floss



Patented Aug. 7, 1945 DENTAL FLOSS Albert A. StonehlllQBrooklyn, N. Y., assignor to Johnson It Johnson, New Brunswick, N. -.I.. a corporation of New Jersey No Drawing. Application April 14, 1942,.

sol-m No. 438,964

6 Claims.

This invention relates to dental floss or tapes which are now generally made of natural fibers suchassilk.

Natural fibers, however, hav'e' a tendency to shred or fray upon use, which tendency not only lessens their tensile strength but prevents or in-- improved dental floss which does not have the' foregoing disadvantages. I

It has been found that a. dental floss 'm'ade from a strand or filament of synthetic fibers of an unplasticized vinyl resin such as a copolymer of vinyl chloride and vinyl acetate treated with wax has unique properties that unexpectedly cause it to be admirably suited for use as a dental floss.

It has been found that the individual filaments or fibers ofa synthetic thread or filament of an 'unplasticized vinyl resin such as a copolymer of vinyl chloride and vinyl acetate due to their thermoplastic characteristics tend to fuse together wh'en it is run through a wax bath at telnperatures ranging between 65 C. and 100 C. This partial fusion of the individual fibers of the filament produces a smooth slick finished floss that is not only considerably more resistant to fraying and wear than floss froni natural fibers. during use but tends to pass between the teeth more readily than natural fiber floss. This latter property may also be due to its smooth surface and its tendency-to shrink when heated to temperatures in excess of 65 C. and the subsequent elasticity of the filament. The elasticity gained is of distinct advantage in aiding passing or drawing of the synthetic floss between-the teeth. In tight spaces, the slight elasticity of the synthetic floss permits the floss to work its way into the space whereas other fibers not possessing this inh'erent elasticity tend to fray and eventear. 45

verysatisfactory inasmuch as it is slightly above the thermoplastic point of the synthetic filament and the congealing point of wax. Temperatures above 100 C. may cause excessive shrinkage and loss of tensile strength.

So far as is known the wax does not enter into a chemical combination with the synthetic fiber although some of the wax may be entrapped between the individual fibers as they fuse together thus insuring an adequate supply of waxin a usable form in the finished product. In any event the finished product due to its fused and non-raveling or fraying characteristic in combinatiorrwith the wax either entrapped or on the 10 surface results in a floss that is elastic, flexible,

smooth and superior in non-fraying and nonraveling characteristics to silk floss heretofore on the market.

Iclaini: a

1. The method of making a dental floss which comprises the steps of forming a thread of a plurality of synthetic fibers of an unplasticized vinyl resin and partially fusing the flberstogether by passing the thread through a wax bath at a temperature between 65 C. and 100 C.

, 2. The method of making a dental floss which comprises the steps of forming a thread of a plurality of synthetic fibers of a copol'ymer of vinyl chloride'and vinyl acetate and p rtially fusing the fibers together by passing the thread through a wax bath. at a temperature between C. and

, 3. An elastic dental fioss having smooth, slip- 30. Dery surfaces, comprising a plurality of synthetic fibers of unplasticized vinyl resin partially fused I together and bonded and impregnated with an adhering wax, said floss being elastic and resistant to shredding and fraying.

fibers of a copolymer of vinyl chloride. and vinyl acetate partially fused together and bonded and impregnated with an adhering wax.

6. The method of making an elastic dental floss which comprises the steps of forming a thread of a plurality of synthetic fibers of an unplastlcized vinyl resinand partially fusing and bonding the fibers together in contact with an adhering wax at temperatures slightlyabove the fusion point of the'flbers and the melting point of the wax, and below the temperature of any substantial shrinking of the-fibers.

4. Anelastic dental floss having smooth, snp- ALBERT A. S'I'ONEHILLK 

